10_Center of Gravity

Center of Gravity

Ms Wida N Agustina

Centre of Gravity

1.The centre of gravity of an object is the
point at which the weight of the object may
be considered to act

2.For example, for a person standing
upright, their centre of gravity is roughly
in the middle of the body behind the navel,
and for a sphere, it is at the centre

3.For symmetrical objects with uniform
density, the centre of gravity is located at
the point of symmetry

Multiple Choice

The point through which the whole weight of the body acts is called

• Center of gravity

• Inertia point

• central point

• centroid

Multiple Choice

Center of gravity of an object depends on it's

• mass

• shape

• density

• area

Multiple Choice

Where the center of gravity of a circle lies?

• Anywhere on its circumference

• At its centre

• Anywhere on its radius

• Anywhere on its diameter

Investigating Center of Gravity for Irregular Object

Multiple Choice

A simple method to find centre of gravity of a body is usage of

• stop watch

• pendulum

• plumb line

• gauge

Multiple Choice

Where do you hang the plumb line when determining the CG?

• It doesn't matter, because it always goes through the CG

• Only from the corners

• From the point where you are suspending the object

• At the right angle

Centre of Gravity vs Centre of Mass

1. In a uniform gravitational field, the centre of
   gravity is identical to the centre of mass

2. ​The centre of mass does not depend on the
   gravitational field

3. Since weight = mass ✕ acceleration due to
   gravity, the centre of gravity does depend on
   the gravitational field

4. When an object is in space, its centre of
   gravity will be more towards the object with
   larger gravitational field for example, the
   Earth’s gravitational field on the Moon​

​

Center of Gravity Affect Stability

●

The position of the centre of
gravity of an object affects
its stability

●

An object is stable when its
centre of gravity lies above
its base

Center of Gravity Affect Stability

●The wider base an object has, the lower its centre of gravity and it is more stable

●The narrower base an object has, the higher its centre of gravity and the object is more likely
to topple over if pushed

Multiple Choice

What is one way you might increase the stability of an object?

• Increase height of the object

• Shorten the base of the object

• Raise the center of gravity

• Lower the center of gravity

Multiple Choice

Which of the cuboids is more stable?

• A

• B

• C

• D